Low power and Lossy Networks (LLNs), e.g., sensor networks, have a myriad of applications, such as Smart Grid and Smart Cities. Various challenges are presented with LLNs, such as lossy links, low bandwidth, battery operation, low memory and/or processing capability, etc. To address the limited resources of LLNs, the Internet Engineering Task Force (IETF) working group for Internet Protocol version 6 (IPv6) over Low power Wireless Personal Area Networks (6LoWPAN) has defined an adaptation layer for carrying IPv6 packets in IEEE 802.15.4 frames. A primary component of the adaptation layer is an IPv6 header compression mechanism that reduces the size of IPv6 payloads to reduce channel utilization, transmission energy cost, and communication latency. Furthermore, because packet error rates and packet length are correlated, reduced packet sizes also serves to reduce packet error rates. Note that other LLN link technologies have also adopted the same (or similar) header compression mechanism, such as IEEE P1901.2 for Power Line Communication (PLC), and others.
The 6LoWPAN header compression mechanism reduces the size of IPv6 addresses by using stateless and context-based techniques. The stateless technique replaces the standard encoding for well-known address formats (e.g., link-local unicast, well-known multicast, and unspecified addresses) with compact forms used, and does not allow for communication across network boundaries. The context-based technique, however, may be used to compact IPv6 addresses by replacing them with a short context identifier that indicates a particular IPv6 prefix (e.g., limited to sixteen different 4-bit identifiers). This mechanism assumes that all 6LoWPAN devices in the same network are configured with the same context information, which requires extra configuration. Currently, however, there is no definition as to how prefixes are selected for compression into context identifiers, nor when context identifiers should be distributed.